BACKGROUND: Oxidative stress plays a crucial role in the female reproductive system. The oxidative balance score (OBS) is a new measure for assessing the balance between antioxidant and pro-oxidative factors in diet and lifestyle. However, limited studies have explored the relationship between OBS and infertility. METHODS: We performed a cross-sectional study including 2,664 women aged 20-45 years, based on data from the 2013-2020 National Health and Nutrition Examination Survey (NHANES). The OBS was derived from 16 dietary components and 4 lifestyle factors. We used multivariate logistic regression analysis to examine the association between OBS and infertility. RESULTS: The analysis revealed a significant negative association between higher OBS and infertility risk, with an odds ratio (OR) of 0.98 (95% CI, 0.95-1.00) after full adjustment. Compared to the first quartile of OBS, the second, third, and fourth quartiles showed ORs of 0.71 (95% CI, 0.45-1.11), 0.79 (95% CI, 0.51-1.22), and 0.57 (95% CI, 0.35-0.92), respectively. Similarly, women in the highest dietary OBS and lifestyle OBS quartiles had a lower infertility risk compared to those in the lowest quartiles, with ORs of 0.60 (95% CI, 0.39-0.94) and 0.54 (95% CI, 0.32-0.93), respectively. Furthermore, subgroup analysis indicated that the association between the fourth quartile of OBS and infertility remained consistent, except among women with other ethnicities-including multi-racial, and college graduate or higher. CONCLUSION: These findings suggest that high dietary OBS and lifestyle OBS are associated with a lower risk of infertility.